Epoxy resin compositions for sealing semiconductors

Abstract

In an epoxy resin composition for sealing a semiconductor element containing about 50 to 85% by weight of an inorganic filler, the improvement wherein the inorganic filler comprises at least a silica powder and a calcium silicate powder, and the amount of said calcium silicate powder is about 20 to 75% by weight and the amount of the silica powder is about 25 to 80% by weight based on the total weight of the silica powder and calcium silicate powder.

What is claimed is: 
     
       1. In an epoxy resin composition for sealing a semiconductor element containing about 50 to 85% by weight of an inorganic filler, the improvement wherein the inorganic filler comprises at least a silica powder and a calcium silicate powder, and the amount of said calcium silicate powder is about 20 to 75% by weight and the amount of the silica powder is about 25 to 80% by weight, based on the total weight of the silica powder and calcium silicate powder. 
     
     
       2. The composition of claim 1, wherein the amount of the calcium silicate powder is about 30 to 60% by weight. 
     
     
       3. The composition of claim 1, wherein the calcium silicate powder is a needle-like material having a particle size (longer diameter) of about 1μ to about 2 mm. 
     
     
       4. The composition of claims 1, 2 or 3, wherein the calcium silicate powder is an acetic acid treated calcium silicate powder. 
     
     
       5. The composition of claim 1, wherein the silica powder is a crystalline silica or an amorphous silica. 
     
     
       6. The composition of claims 1 or 5, wherein the silica powder has an average particle size of about 5 to 10μ with the maximum particle size being about 100μ. 
     
     
       7. The composition of claim 3, wherein said calcium silicate powder is wollostonite. 
     
     
       8. The composition of claim 1, wherein said composition is fire retardant. 
     
     
       9. In a semiconductor which is sealed with an epoxy resin composition, the improvement in which said resin composition comprises about 50 to 85% by weight of an inorganic filler, which comprises at least a silica powder and a calcium silicate powder, and the amount of said calcium silicate powder is about 20 to 75% by weight and the amount of the silica powder is about 25 to 80% by weight, based on the total weight of the silica powder and calcium silicate powder. 
     
     
       10. The semiconductor of claim 9, wherein the amount of the calcium silicate powder is about 30 to 60% by weight. 
     
     
       11. The semiconductor of claim 9, wherein the calcium silicate powder is a needle-like material having a particle size (longer diameter) of about 1μ to about 2 mm. 
     
     
       12. The semiconductor of claims 9, 10 or 11, wherein the calcium silicate powder is an acetic acid treated calcium silicate powder. 
     
     
       13. The semiconductor of claim 9, wherein the silica powder is a crystalline silica or an amorphous silica. 
     
     
       14. The semiconductor of claims 9 or 13, wherein the silica powder has an average particle size of about 5 to 10μ with the maximum particle size being about 100μ. 
     
     
       15. The semiconductor of claim 11, wherein said calcium silicate powder is wollostonite. 
     
     
       16. The semiconductor of claim 9, wherein said composition is fire retardant. 
     
     
       17. The composition of claim 1, wherein the amount of inorganic fillers other than silica powder and calcium silicate powder is less than 45 parts by weight per 100 parts by weight silica and calcium silicate powder. 
     
     
       18. The semiconductor of claim 9, wherein the amount of inorganic fillers other than silica powder and calcium silicate powder is less than 45 parts by weight per 100 parts by weight silica and calcium silicate powder. 
     
     
       19. The composition of claim 1, wherein said inorganic filler consists of silica and calcium silicate powder. 
     
     
       20. The semiconductor of claim 9, wherein said inorganic filler consists of silica and calcium silicate powder.